1. Field of the Invention
The present invention relates generally to optical disk apparatuses, and more particularly, to an optical disk apparatus which has a cover to cover and uncover an objective lens provided in an optical pickup, thus preventing the objective lens from being contaminated with dust, etc.
2. Description of the Related Art
As well known to those skilled in the art, optical disks are used as a medium to record information and to reproduce the recorded information. The optical disks allow information to be recorded onto and to be reproduced from the optical disks without being in contact with separate heads for recording and reproducing the information. Furthermore, the optical disks have high recording density. Generally, recorded information on the optical disks is read and reproduced by optical disk apparatuses.
Typically, the conventional optical disk apparatuses each include a turntable to seat an optical disk thereon, and a spindle motor to rotate the turntable. The optical disk apparatus further includes an optical pickup with an objective lens, and an actuating unit to reciprocate the optical pickup in a radial direction of the optical disk. It is very important to protect the objective lens, which directly irradiates light on a surface of the optical disk, on which the information is recorded, from outside contaminants, such as dust.
If a contaminant, such as dust, is smeared on the objective lens, the performance of the objective lens may be deteriorated. In addition, if the objective lens were contaminated, the optical disk may become illegible. Furthermore, when information is recorded onto the optical disk using the objective lens contaminated, the recording property of the optical disk may be deteriorated. Particularly, to use the optical disk apparatus in a place in which dust is excessively generated, for example, a desert region, such as the Middle East, or an industrial floor in which excessive fly dust is generated, a dust protective means must be provided in the optical disk apparatus to protect the objective lens from the dust.
To achieve the above-mentioned purpose, several optical disk apparatuses having structures to protect outer surfaces of objective lenses from dusts were proposed and have been used. Representative examples of the conventional optical disk apparatuses will be described herein below, with reference to the drawings.
FIG. 1 is a view showing an example of the conventional optical disk apparatuses. As shown in FIG. 1, a conventional optical disk apparatus includes a turntable 22 to place an optical disk 10 thereon, and a spindle motor 20 which is coupled to the turntable 22. The optical disk apparatus further includes an optical pickup 30 which is provided around the spindle motor 20 and is supported by a guide 42. The optical pickup 30 reciprocates in a radial direction of the optical disk 10 which is shown by the arrow (B) in FIG. 1. The optical disk apparatus further includes an optical pickup actuating unit 40 to actuate the optical pickup 30. The optical disk apparatus further includes a body cover 70 which is rotated around a hinge shaft 72 in directions shown in the arrow (A) in FIG. 1. The optical disk apparatus further includes a locking unit 74 and a control unit 50 which is coupled to the optical pickup actuating unit 40.
In the conventional optical disk apparatus, the body cover 70 is rotated to open an upper portion of the optical disk apparatus. Thereafter, the optical disk 10 is placed onto or removed from the turntable 22 through the opened upper portion of the optical disk apparatus. When the optical disk 10 is placed onto the turntable 22, the optical pickup 30 with an objective lens 32 moves to a position, on which a sensor 44 is provided, to wait under a lens cover 60. In other words, in a state in which the optical disk 10 is not mounted onto the turntable 22, the optical pickup 30 is placed under the lens cover 60. Therefore, the objective lens 32 is protected by the lens cover 60 from contamination such as dust.
However, in the conventional optical disk apparatus, the lens cover 60 must be additionally provided in the optical disk apparatus to have the above-mentioned structure. Accordingly, the optical disk apparatus must be increased in size to receive the lens cover 60 therein. In a detailed description, the optical disk apparatus is designed such that the optical pickup reciprocates in an additional region, on which the lens cover 60 is provided, as well as a region having a predetermined area to correspond to a diameter of the optical disk. Therefore, the optical disk apparatus is disadvantageous in that its size is increased.
FIG. 2 is a perspective view showing another example of optical pickup of the conventional optical disk apparatuses. As shown in FIG. 2, a conventional optical pickup 130 includes an optical pickup body 134 and an actuator 180 which is provided on the optical pickup body 134, with an objective lens 132 provided in the actuator 180. The optical pickup 130 further includes a cover 160 which is actuated on the actuator 180 by a cover actuating means 162.
In the conventional optical pickup 130 having the above-mentioned construction, the cover 160 covers the objective lens 132 and is removed from the objective lens 132. The above-mentioned operation of the cover 160 protects the objective lens 132 from dust. Furthermore, a fine cleaning means (not shown), such as fine wool, may be provided under the cover 160 to clean the surface of the objective lens 132.
However, to provide the above-mentioned structure, the conventional optical pickup 130 must have the additional cover actuating means 162 to actuate the cover 160, as shown in FIG. 2. Therefore, the optical pickup body 134 including the cover actuating means 162 is increased in size.
As described above, each of the structures adapted for the conventional optical disk apparatus and the conventional optical pickup protects the objective lens from dust, but is problematic in that its size must be increased to achieve the above-mentioned purpose. Furthermore, in the case of the optical disk apparatus shown in FIG. 1, a gap exists between the lens cover 60 and the objective lens 32. Accordingly, the optical disk apparatus is problematic in that the objective lens 32 is not completely protected from dust.